The high, open moorland of Exmoor experiences large quantities of rainfall which can exceed 200cm annually. This rainfall is initially drawn into spongy, peaty soils. Over the course of the year however, it dribbles out, running down the steep slopes and into the valleys or 'combes' as they're known in North Devon. This begins the river's journey to the sea.
Even here at the SOURCE and upper reaches, fish can be found. The most common of which being the minnow (Phoxinus phoxinus) (<10cm). These small fish are normally found sticking together in shoals, picking away at plant matter and insect larvae drifting by in the strong river currents. Their shoaling habits provides some protection from predatory fish and birds, such as the kingfisher, dipper and heron.
Within the strong current predatory fish such as the brown trout (Salmo trutta)(<30cm) can be seen holding it's position. Their torpedo shape, large fins and tail provide near-perfect design for manoeuvring at speed through the water in order to catch their prey. This usually consists of drifting insect nymphs and larvae, or even small fish.
Within the large stones and boulders that occupy the bottom, the stone loach (Noemacheilus barbatulus) (< 12cm) can sometimes be spotted. It is more a night feeder using it's slender body shape and mouth feelers or barbels to wriggle about and locate it's prey of small invertebrates. The bullhead (Cottus gobio)( < 10cm) can also be found. These solitary fish remain still, blending in with the surrounding stones. They lie in wait for the opportunity to zoom out and pounce on their unsuspecting prey using their large gaping mouth.